What Is a Heart Murmur?

A heart murmur is an extra or unusual sound heard during the heartbeat cycle, ranging from very faint to very loud. Through a stethoscope, a heart murmur sounds like whooshing or swishing.

Heart murmurs can be present at birth or develop throughout a person’s life. Often, heart murmurs are harmless, but some may indicate an underlying heart condition. The former are known as innocent heart murmurs; the latter as worrisome heart murmurs. Heart murmur symptoms can vary and may be absent in some cases.

Baptist Health is known for advanced, superior care for patients with heart disease and the diagnosis, management, and treatment of heart murmur. You will appreciate timely appointments and respectful attention to your concerns, all in a positive and friendly atmosphere. Here, you have access to the region’s most comprehensive, multidisciplinary team of specialists and innovative therapies, including many available only through specialized clinical trials. In every way, we work to demonstrate the utmost in excellent care to those who trust us with their health.

Types of Heart Murmurs

There are three main types of heart murmurs. All murmurs are graded on volume, pitch, duration, location, and frequency.

The three types of heart murmurs are:

• Diastolic murmur: A diastolic murmur is a murmur that occurs during the relaxation phase of your heart. For example, when your heart wall relaxes in between each contraction.
• Systolic murmur: A systolic murmur is a murmur during a contraction of your heart. There are two subtypes of systolic murmurs: ejection murmurs and regurgitation murmurs. In ejection, blood flows through a constricted artery. In regurgitation murmurs, blood flows backward.
• Continuous murmur: A continuous murmur occurs during both contraction and relaxation.

Symptoms

Heart murmurs often present without symptoms other than an unusual heartbeat sound. This is true of innocent or harmless heart murmurs. Innocent heart murmurs are common in infants and young children.

Worrisome heart murmurs are those with symptoms that accompany an unusual heartbeat. When these other symptoms are present, it may indicate an underlying heart problem and shouldn’t be ignored. Worrisome or abnormal heart murmur symptoms include:

• Blue-tinged skin
• Chest pain
• Chronic cough
• Dizziness
• Enlarged liver
• Enlarged neck veins
• Fainting
• Heavy sweating, not related to exercise
• Poor appetite
• Poor growth (in infants)
• Shortness of breath
• Swelling or sudden weight gain.

Causes

A heart murmur is the result of unusually quick or turbulent blood flow through the heart. There is a wide range of potential heart murmur causes. These differ by type of murmur.

Innocent Heart Murmur Causes

Persons with an innocent heart murmur rarely show evidence for tissue damage or other cardiac conditions. Heart murmur causes of a generally harmless nature include:

• Anemia
• Fever
• Hyperthyroidism (an overactive thyroid)
• Exercise or athletic activity
• Periods of rapid growth, such as adolescence
• Pregnancy.

Worrisome Heart Murmur Causes

The more serious forms of a heart murmur can affect either children or adults. In children, the causes tend to be congenital, that is, individuals are born with a structural defect of the heart. In adults, heart murmur causes develop over time and usually involve some form of valve disease.

Worrisome heart murmur causes include:

• Cardiac shunts: A cardiac shunt is a structural defect in the heart that interrupts or disturbs blood flow. It is a congenital condition mostly affecting children.
• Holes in the heart: These holes are muscle-wall gaps that form between the upper or lower chambers of the heart. This is another congenital condition found in children.
• Endocarditis: Endocarditis is bacterial infection of the heart. If it spreads to the valves, it can result in a murmur.
• Calcium deposits: Calcium can build up over time in heart valves, a condition known as valve stenosis. The calcified valve stiffens and narrows, reducing blood flow or blocking it from operating correctly. A heart murmur is one possible consequence.
• Rheumatic fever: Rheumatic fever is an acute form of strep throat, occurring mostly in persons that forgo proper treatment. It can impact the heart valves and result in a heart murmur. It is relatively uncommon in the U.S.

Risk Factors

Risk factors that could contribute to an abnormal heart murmur include:

• Certain medical conditions: Hyperthyroidism (too much thyroid hormone), high blood pressure in the lungs (pulmonary hypertension), carcinoid syndrome (related to intestinal cancer), lupus, rheumatoid arthritis, and other conditions can increase the risk of an abnormal heart murmur.
• Endocarditis: This infection of the heart’s inner lining typically occurs when bacteria from the mouth or elsewhere get into the bloodstream and lodge in the heart.
• Family history of heart defects: Blood relatives often share heart defects that can cause heart murmurs.
• Heart valve abnormalities: Congenital heart valve conditions, including valves that don’t allow enough blood flow (stenosis) or those that don’t close properly (regurgitation) – such as in mitral valve prolapse – can lead to a heart murmur.
• Holes in the heart or cardiac shunts: Holes, or septal defects, can be present at birth and may or may not be serious. Cardiac shunts occur when there’s an abnormal blood flow between the heart chambers or blood vessels.
• Illnesses during pregnancy: Some conditions affecting a mother, like uncontrolled diabetes or a rubella infection, can lead to defects and a heart murmur in her baby.
• Maternal use of certain medications or drugs: Use of certain medications, alcohol or drugs can cause heart defects in a developing baby.
• Rheumatic fever: Rare in the United States and other developed countries, this illness can occur without prompt or complete treatment of a strep throat infection – damaging the heart valves.
• Valve calcification: This hardening of valves – like in mitral or aortic valve stenosis – can impede blood flow and occurs as a person ages.

Diagnosis

To determine if a patient has a heart murmur, and identify the type, the physician will listen to the patient’s heart with a stethoscope during a physical examination. The physician will assess the murmur’s volume, pitch, location, timing, location, and length and examine the patient for any other signs and symptoms of heart problems.

If the physician needs more information, or thinks the heart murmur may be abnormal, he or she may order diagnostic procedures including:

• Chest X-ray: A common imaging test of the heart and aorta, which can identify enlargement.
• Cardiac catheterization: A long, thin flexible tube is threaded through a blood vessel in the arm or groin and to the heart. Contrast material is injected through the tube and a type of X-ray movie is taken to show how the aortic valve functions and measure pressure in the heart chambers.
• Echocardiogram: This ultrasound exam uses soundwaves to take moving pictures of the heart’s chambers and valves. It can identify abnormal heart valves, such as those that are hardened or leaking, and can detect most heart defects.
• Electrocardiogram (EKG): This test measures the electrical activity of the heart and can help determine if parts of the heart are enlarged or overworked. The heart’s electrical currents are detected by 12 to 15 electrodes that are attached to the arms, legs, and chest via sticky tape.

Heart Murmur Prognosis

Many heart murmurs are considered harmless and are left untreated. These are known as innocent heart murmurs.

Prognosis for abnormal heart murmurs depends on the type and severity of the heart problem causing them.

Treatment

An innocent heart murmur typically does not require treatment, though medications or supplements may be prescribed if an innocent heart murmur is due to hyperthyroidism or anemia.

Abnormal heart murmur treatment depends on its type, cause, the presence of heart disease, and your overall health.

Medications

The heart murmur medication your doctor prescribes will depend on your specific heart problem.

They may include:

• Angiotensin-converting enzyme (ACE) inhibitors, which lower blood pressure
• Anticoagulants, which prevent blood clots from forming and causing a heart attack or stroke
• Beta blockers, which lower the heart rate and blood pressure
• Diuretics, which remove excess fluid from the body
• Statins, which lower cholesterol, which can worsen some heart problems

Surgery

If you have a heart valve condition that can’t be treated with medication alone, your doctor may recommend one of these procedures:

• Annuloplasty, in which a surgeon tightens tissue around the valve by implanting an artificial ring – closing abnormal openings
• Balloon valvuloplasty, during which a small catheter containing an expandable balloon is threaded into your heart, placed into the valve, and expanded to widen a narrowed valve
• Structural support repair, during which a surgeon replaces or shortens cords that support the valves. With cords and muscles the right length, the valve leaflet edges meet, eliminating the leak.
• Valve leaflet repair, during which the surgeon separates, cuts or pleats a valve flap

Valve Replacement

In some cases, a valve must be replaced. Options include:

• Open-heart surgery: During this procedure, the surgeon removes a narrowed valve and replaces it with a mechanical or tissue valve. Mechanical valves, made from metal, are durable, but carry the risk of blood clots. Tissue valves – which come from a deceased human donor, pig, or cow – need eventual replacement.
• Transcatheter aortic valve replacement (TAVR): This less-invasive approach involves replacing the aortic valve with a prosthetic valve via an artery in the leg or a small incision in the chest.

Recovery from open-heart surgery can take four to eight weeks and include a one-to-three-day stay in the intensive care unit, rehabilitation, and a gradual return to everyday activities.

Prevention

There is no proven means of preventing heart murmurs. That said, a healthy lifestyle can reduce the possibility of developing a heart murmur in adults, by lessening some of the contributing factors. Childhood heart murmurs often fade away as young persons grow into adulthood.

Complications

Innocent heart murmurs don’t cause complications.

Abnormal heart murmurs themselves don’t cause complications, but underlying conditions may cause serious complications such as heart attack or stroke, heart failure, poor growth (in infants and children), and other serious issues.